选择 UITableView 时使内容可见

Question

我正在使用此方法在选中时放大我的单元格的高度。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
  [tableView beginUpdates];
  [tableView endUpdates];
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
  if([indexPath isEqual:[tableView indexPathForSelectedRow]]) {
      return 100.0;
  }

  return 44.0;
}

我想在单元格放大时才可见的区域显示一个UIImageView，取消选择单元格时隐藏。

Answer 1

您的代码看起来可以正确放大单元格。

您也可以按照下面提到的步骤进行同样的操作 -

1) 添加一个属性以跟踪所选单元格

@property (nonatomic) int currentSelectedRow;

2) 用一个值初始化它

self.currentSelectedRow = -1;

3) Return 单元格高度

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath 
{
     if([indexPath row] == self.currentSelectedRow) {
          return 100.0;
 }

     return 44.0;
}

4) 单元格选择方式设置选中行

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{
        // code to do on cell selection

        // set the row number of current selected cell
        self.currentSelectedRow = indexPath.row;

        // animate the selected row
        [tableView beginUpdates];
        [tableView endUpdates];
}

5) 在单元格取消选择方法中将选中的行设置为无效行号(-1)

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath 
{       

        // invalid row number
        self.currentSelectedRow = -1;

        // animate the selected row
        [tableView beginUpdates];
        [tableView endUpdates];
}

注意:这只是一个示例代码，您可以根据自己的需要进行定制。

Answer 2

这是一个简单的例子

NSInteger selectedIndex;

- (void)viewDidLoad
{
   [super viewDidLoad];
   // Do any additional setup after loading the view, typically from a nib.

    UITableView *tbl=[[UITableView alloc]initWithFrame:CGRectMake(0, 75, 320, 300)];
    [tbl setDelegate:self];
    [tbl setDataSource:self];
    [self.view addSubview:tbl];

    selectedIndex=-1;
 }


-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
   return 8;
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
   UITableViewCell *cell=[[UITableViewCell alloc]init];

   UILabel *lbl=[[UILabel alloc]initWithFrame:CGRectMake(10, 0, 70, 40)];
   [lbl setText:@"cell"];
   [cell addSubview:lbl ];

    UIImageView *imgVw=[[UIImageView alloc]initWithFrame:CGRectMake(100, 6, 50, 30)];
   [imgVw setBackgroundColor:[UIColor clearColor]];
   [imgVw setTag:400+indexPath.row];
   [imgVw setAlpha:0.0];
   [cell addSubview:imgVw];

   return cell;

}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

   UITableViewCell *cell=[tableView cellForRowAtIndexPath:indexPath];

   [tableView beginUpdates];

   UIImageView *imgVwCellBg=(UIImageView*)[cell viewWithTag:400+indexPath.row];

   if (selectedIndex==indexPath.row)
   {
      selectedIndex=-1;
      [imgVwCellBg setAlpha:0.0];
   }
   else
   {
      selectedIndex=indexPath.row;
      [imgVwCellBg setBackgroundColor:[UIColor brownColor]];
      [imgVwCellBg setAlpha:1.0];
   }

   [tableView endUpdates];
}

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
   UITableViewCell *cell=[tableView cellForRowAtIndexPath:indexPath];
   UIImageView *imgVwCellBg=(UIImageView*)[cell viewWithTag:400+indexPath.row];

   selectedIndex=-1;

   [imgVwCellBg setAlpha:0.0];

}


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{

   if(selectedIndex==indexPath.row)
   {
      return 100;
   }
   else
   {
      return 44;
   }

}

Answer 3

试一次

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 4;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell;
    if (cell == nil) {
        cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"identifier"];
    }

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 5, 200, 0)];
    [imageView setTag:1000];
    [imageView setImage:[UIImage imageNamed:@"Image_2"]];
    [cell addSubview:imageView];

    return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell *cell = (UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath];

    [tableView beginUpdates];
    UIImageView *imageView = (UIImageView *)[cell viewWithTag:1000];

    if (selectedIndex==indexPath.row)
    {
        selectedIndex=-1;
        [UIView animateWithDuration:0.4 animations:^{
        [imageView setFrame:CGRectMake(20, 5, 200, 0)];
        }];
    }
    else
    {
        selectedIndex = indexPath.row;
        [UIView animateWithDuration:0.4 animations:^{
        [imageView setFrame:CGRectMake(20, 5, 200, 170)];
        }];
    }
    [tableView endUpdates];

}

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = (UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath];

    [tableView beginUpdates];

    [UIView animateWithDuration:0.4 animations:^{
    UIImageView *imageView = (UIImageView *)[cell viewWithTag:1000];
    [imageView setFrame:CGRectMake(20, 5, 200, 0)];
}];

    [tableView endUpdates];
}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(selectedIndex == indexPath.row)
    {
        return 200;
    }
    else
    {
        return 75;
    }
    return 0;
}

Answer 4

我认为问题可能是 NSIndexPath 的 isEuqal: 方法，不像 NSString，你不能只用用户 isEuqal: 来判断 NSIndexPath 是否相等。

  if([indexPath isEqual:[tableView indexPathForSelectedRow]]) {

替换为

NSIndexPath *selectedPath = [tableView indexPathForSelectedRow];
if(selectedPath.row == indexPath.row && selectedPath.section == indexPath.section){

Answer 5

好的，这就是我所做的，使用你给我的一切并做到这一点

 @property (nonatomic) int currentSelectedRow;
- (void)viewDidLoad {
[super viewDidLoad];
self.currentSelectedRow = -1;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString * cellId = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId forIndexPath:indexPath];
UIImageView *contentView = (UIImageView *)[cell viewWithTag:304];
contentView.hidden = YES;



return cell;

}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = (UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath];
self.currentSelectedRow = indexPath.row;



[tableView beginUpdates];
UIImageView *contentView = (UIImageView *)[cell viewWithTag:304];
contentView.hidden = NO;

if (_currentSelectedRow == indexPath.row)
{

    [UIView animateWithDuration:0.4 animations:^{

        [contentView setFrame:CGRectMake(20, 5, 200, 0)];
    }];
}
else
{
    _currentSelectedRow = indexPath.row;
    [UIView animateWithDuration:0.4 animations:^{
        contentView.hidden = NO;
        [contentView setFrame:CGRectMake(20, 5, 200, 170)];
    }];
}

[tableView endUpdates];



}
- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = (UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath];
UIImageView *contentView = (UIImageView *)[cell viewWithTag:304];
contentView.hidden = YES;

// invalid row number
self.currentSelectedRow = -1;

// animate the selected row
[tableView beginUpdates];
[tableView endUpdates];
}


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if([indexPath row] == self.currentSelectedRow) {
    return 100.0;
}

return 44.0;
}

感谢您的参与一定要给这个问题投票，它会对很多人有帮助

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